As an important part of railway lines, the healthy service status of track fasteners was very important to ensure the safety of trains. The application of deep learning algorithms was becoming an important method to r...As an important part of railway lines, the healthy service status of track fasteners was very important to ensure the safety of trains. The application of deep learning algorithms was becoming an important method to realize its state detection. However, there was often a deficiency that the detection accuracy and calculation speed of model were difficult to balance, when the traditional deep learning model is used to detect the service state of track fasteners. Targeting this issue, an improved Yolov4 model for detecting the service status of track fasteners was proposed. Firstly, the Mixup data augmentation technology was introduced into Yolov4 model to enhance the generalization ability of model. Secondly, the MobileNet-V2 lightweight network was employed in lieu of the CSPDarknet53 network as the backbone, thereby reducing the number of algorithm parameters and improving the model’s computational efficiency. Finally, the SE attention mechanism was incorporated to boost the importance of rail fastener identification by emphasizing relevant image features, ensuring that the network’s focus was primarily on the fasteners being inspected. The algorithm achieved both high precision and high speed operation of the rail fastener service state detection, while realizing the lightweight of model. The experimental results revealed that, the MAP value of the rail fastener service state detection algorithm based on the improved Yolov4 model reaches 83.2%, which is 2.83% higher than that of the traditional Yolov4 model, and the calculation speed was improved by 67.39%. Compared with the traditional Yolov4 model, the proposed method achieved the collaborative optimization of detection accuracy and calculation speed.展开更多
星基增强系统(SBAS)中生命安全服务不仅能提高定位精度,也能改善系统完好性,目前在民航系统中已经进行相关的应用研究。RTCA DO 229D文件中规定了SBAS接收机的性能标准,对于安全性要求较高的民航用户根据这个标准制定了相应接收机生产...星基增强系统(SBAS)中生命安全服务不仅能提高定位精度,也能改善系统完好性,目前在民航系统中已经进行相关的应用研究。RTCA DO 229D文件中规定了SBAS接收机的性能标准,对于安全性要求较高的民航用户根据这个标准制定了相应接收机生产规范和指南。但对于安全性要求较低的用户接收机还没有形成相应的规范。除生命安全服务外,EGNOS自2009年起就提供了开放服务(OS),接收机制造商也生产了相应的接收机产品,但存在接收机设计欠佳的缺点。主要研究基于开放服务的接收机设计的关键技术,为GNSS接收机制造商如何利用EGNOS广播信息来提高OS的定位精度制定一套明确的标准,同时,也为北斗星基增强系统接收机制造商提供了一定的借鉴意义。展开更多
文摘As an important part of railway lines, the healthy service status of track fasteners was very important to ensure the safety of trains. The application of deep learning algorithms was becoming an important method to realize its state detection. However, there was often a deficiency that the detection accuracy and calculation speed of model were difficult to balance, when the traditional deep learning model is used to detect the service state of track fasteners. Targeting this issue, an improved Yolov4 model for detecting the service status of track fasteners was proposed. Firstly, the Mixup data augmentation technology was introduced into Yolov4 model to enhance the generalization ability of model. Secondly, the MobileNet-V2 lightweight network was employed in lieu of the CSPDarknet53 network as the backbone, thereby reducing the number of algorithm parameters and improving the model’s computational efficiency. Finally, the SE attention mechanism was incorporated to boost the importance of rail fastener identification by emphasizing relevant image features, ensuring that the network’s focus was primarily on the fasteners being inspected. The algorithm achieved both high precision and high speed operation of the rail fastener service state detection, while realizing the lightweight of model. The experimental results revealed that, the MAP value of the rail fastener service state detection algorithm based on the improved Yolov4 model reaches 83.2%, which is 2.83% higher than that of the traditional Yolov4 model, and the calculation speed was improved by 67.39%. Compared with the traditional Yolov4 model, the proposed method achieved the collaborative optimization of detection accuracy and calculation speed.
文摘星基增强系统(SBAS)中生命安全服务不仅能提高定位精度,也能改善系统完好性,目前在民航系统中已经进行相关的应用研究。RTCA DO 229D文件中规定了SBAS接收机的性能标准,对于安全性要求较高的民航用户根据这个标准制定了相应接收机生产规范和指南。但对于安全性要求较低的用户接收机还没有形成相应的规范。除生命安全服务外,EGNOS自2009年起就提供了开放服务(OS),接收机制造商也生产了相应的接收机产品,但存在接收机设计欠佳的缺点。主要研究基于开放服务的接收机设计的关键技术,为GNSS接收机制造商如何利用EGNOS广播信息来提高OS的定位精度制定一套明确的标准,同时,也为北斗星基增强系统接收机制造商提供了一定的借鉴意义。
